Diagnosis and management of acute encephalitis.

Encephalitis is typically viral (approximately half of diagnosed cases) or autoimmune (about a quarter) with the remainder remaining undiagnosable at this time. All require general supportive care but only a minority requires intensive care admission - in these intubation, to protect the airway or to treat status epilepticus with anesthetic drugs, may be needed. In some dysautonomia with wide blood pressure fluctuations is the principal concern. Remarkably, in addition to supportive care, specific treatment options are available for the majority - immune-modulating therapy for those with autoimmune disorders, antiviral therapy for herpes simplex 1 and 2, and varicella-zoster encephalitis. Flavivirus infections (West Nile, Japanese encephalitis, tick-borne encephalitis) remain the most common other identified cause of encephalitis but no specific intervention is available. Overall long-term outcomes are favorable in the majority of patients with encephalitis, a proportion that hopefully will improve with further advances in diagnostic technology and therapeutic interventions.